JP2004022191A - Manufacturing method of fuel cell separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a fuel cell separator in which the separator can be manufactured simply and output degradation of the fuel cell can be suppressed. <P>SOLUTION: In the manufacturing method of the fuel cell separator, the core 50 is formed by water soluble polymer and this core 50 is arranged in a die 60, and an anode side electrode diffusion layer 15 is arranged in the gap between the core 50 and the cavity face 63a. After a molten resin is filled in the cavity 63 and, by solidifying the molten resin, the first separator 20 is formed integrally with the core 50 and the anode side electrode diffusion layer 15, and the core 50 is eluted with water 66. Thereby, by the first separator 20 and the anode side electrode diffusion layer 15, a fuel gas passage 26 can be formed in the first separator 2. <P>COPYRIGHT: (C)2004,JPO

Description

【００５５】
第１比較例は、第１セパレータとアノード側電極拡散層とを一体化しないで、第１セパレータにアノード側電極拡散層を合わせて接触させたものである。
第１実施例は、第１セパレータとアノード側電極拡散層とを一体化した第１実施形態のものである。
【００５６】
第１比較例と第１実施例との抵抗過電圧を以下の条件で測定した。
すなわち、セルモジュールの温度を８０℃に設定し、アノードガス（燃料ガス）として純Ｈ_２を供給するとともに、カソードガス（酸化剤ガス）として空気を供給した。
なお、アノード側の燃料ガス温度を８０℃、カソード側の酸化剤ガス温度を８０℃とし、アノード側の燃料ガス圧力を５０ｋＰａ、カソード側の酸化剤ガス圧力を１００ｋＰａとした。この条件下において、電流密度が０．８８３Ａ／ｃｍ^２の電流を流した。
【００５７】
この結果、第１実施例の抵抗過電圧を、第１比較例の抵抗過電圧と比較して、１セルモジュール当たり０．０１４Ｖ減らすことができた。
よって、第１実施例（第１実施形態）のように、第１セパレータとアノード側電極拡散層とを一体化することにより、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができることが分かる。
【００５８】
次に、第２実施形態及び第４実施形態について説明する。なお、第２、第３実施形態において第１実施形態と同一部材については同一符号を付して説明を省略する。
図９（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第２実施形態）を説明する工程図である。
（ａ）において、中子成形型７６を型締めした状態で、中子成形型７６のキャビティ７６ａ内に、溶融状態の水溶性ポリマーを矢印▲３▼の如く充填する。水溶性ポリマーを凝固させて中子５０を成形した後、可動型７７を矢印の如く上昇する。
【００５９】
（ｂ）において、可動型７７を上昇することで型開きした中子成形型７６のキャビティ７６ａ内から中子５０を取り出す。
（ｃ）において、金型６０の固定型６１に中子５０をセットし、中子５０をセットした後、中子５０にアノード側電極拡散層１５を矢印の如く載せる。このように、中子５０や、アノード側電極拡散層１５をキャビティ６３内にセットした後、可動型６２を矢印の如く下降して金型６０を型締めする。
【００６０】
これにより、第１実施形態の図６（ｂ）の状態になる。以下、第１実施形態と同様の工程を順次繰り返すことにより、図１に示すアノード側電極拡散層１５に一体に形成した第１セパレータ２０を得ることができる。
さらに、図９と同様の工程で、図１に示すカソード側電極拡散層３５に一体に形成した第２セパレータ４０を得ることができる。
【００６１】
第２実施形態によれば、第１実施形態と同様の効果を得ることができる。
また、第２実施形態の燃料電池用セパレータの製造方法によれば、中子５０をアノード側電極拡散層１５と個別に成形することができる。これにより、中子５０の成形方法を第１、第２実施形態のうちのいずれか一方から適宜選択することができるので、設計の自由度を高めることができる。
【００６２】
次に、第３実施形態を図１０〜図１６に基づいて説明する。
図１０は本発明に係る燃料電池用セパレータ（第３実施形態）を備えた燃料電池の分解斜視図を示す。
燃料電池８０は、電解質膜１２にアノード側電極１３及びカソード側電極１４を添わせ、アノード側電極１３側にアノード側電極拡散層１５を介してセパレータ（燃料電池用セパレータ）８２を合わせるとともに、カソード側電極１４側にカソード側電極拡散層３５を介してセパレータ８２を合わせることによりセルモジュール８１を構成したものである。
【００６３】
図１１は図１０の１１−１１線断面図である。
セパレータ８２は、燃料ガス通路形成面（セパレータの両面のうちの一方の面）８２ａ側にアノード側電極拡散層１５を一体に成形することで、燃料ガス通路形成面８２ａ側に燃料ガス通路（ガス通路）８４・・・を多数本条形成する。
【００６４】
また、セパレータ８２は、酸化剤ガス通路形成面（セパレータの両面のうちの他方の面）８２ｂ側にカソード側電極拡散層３５を一体に成形することで、酸化剤ガス通路形成面８２ｂ側に酸化剤ガス通路（ガス通路）８６・・・を多数本条形成する。
さらに、セパレータ８２は、燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・間に冷却水通路８５・・・を多数本条備える。
【００６５】
セパレータ８２を構成する樹脂としては、第１実施形態と同様に、一例として耐酸性を備えた熱可塑性樹脂に、天然黒鉛、人造黒鉛、ケッチェンブラック、アセチレンブラックなどを単独或いは混合配合し、炭素材料を６０〜９０ｗｔ％含んだ樹脂組成物が該当する。
【００６６】
耐酸性を備えた熱可塑性樹脂としては、例えばエチレン・酢ビ（酢酸ビニル）共重合体、エチレン・エチルアクリレート共重合体、直鎖状低密度ポリエチレン、ポリフェニレンサルファイド、変性ポリフェニレンオキサイドなどが該当するが、これに限定するものではない。
【００６７】
図１０に戻って、燃料ガス通路８３・・・（図１１に示す）に、セパレータ８２の上端左側の燃料ガス供給孔部９１ａを連通するとともに、セパレータ８２の下端右側の燃料ガス排出孔部９１ｂを連通する。
また、酸化剤ガス通路８４・・・（図１１も参照）に、セパレータ８２の上端右側の酸化剤ガス供給孔部９２ａを連通するとともに、セパレータ８２の下端左側の酸化剤ガス排出孔部９２ｂを連通する。
さらに、冷却水通路８５・・・（図１１に示す）に、セパレータ８２の上端中央の冷却水供給孔部９３ａを連通するとともに、セパレータ８２の下端中央に冷却水排出孔部９３ｂを連通する。
【００６８】
すなわち、第３実施形態の燃料電池用セパレータ８２は、燃料ガス通路８３・・・と酸化剤ガス通路８４・・・との間に冷却水通路８５・・・を成形することで、第１実施形態の第１、第２セパレータ２０，４０を一体成形した点で、第１実施形態と異なるだけで、その他の構成は第１実施形態と同じである。
このように、第１、第２セパレータ２０，４０を一体成形することで、一対のセパレータ２０，４０間に発生する電気的な接触抵抗をなくして、燃料電池の出力低下をより好適に防ぐことができる。
【００６９】
次に、燃料電池用セパレータの製造方法を図１２〜図１６に基づいて説明する。
先ず、図１２〜図１４に基づいて水溶性ポリマーで燃料ガス通路８３・・・、酸化剤ガス通路８４・・・及び冷却水通路８５・・・（図１１に示す）を形成するための中子１００（図１４に示す）を成形する工程について説明する。
なお、中子１００は、第１ガス通路用中子、第２ガス通路用中子及び冷却水通路用中子からなり、第１ガス通路用中子、第２ガス通路用中子及び冷却水通路用中子の製造工程を以下に説明する。
【００７０】
なお、中子１００は、第１実施形態と同様に水溶性ポリマーで成型する。水溶性ポリマーとしては、例えばポリアクリルアミド、ポリアクリル酸、ポリメタクリル酸、ポリイタコン酸、ポリビニルアルコールなどが該当するが、これに限るものではない。
すなわち、水溶性ポリマーとしては、中子として使用することが可能で、水溶性を備えたものであればよい。
【００７１】
図１２（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第１工程図であり、燃料ガス通路８３・・・（図１１に示す）の第１ガス通路用中子を成形する例について説明する。
（ａ）において、中子成形型８６を型開きした状態で、可動型８７にアノード側電極拡散層１５をセットした後、可動型８７を矢印の如く固定型８８に向けて下降して中子成形型８６を型締めする。
【００７２】
（ｂ）において、中子成形型８６のキャビティ８６ａ内に、溶融状態の水溶性ポリマーを矢印▲４▼の如く充填する。水溶性ポリマーを凝固させて、第１ガス通路用中子１０１をアノード側電極拡散層１５と一体に成形（すなわち、一体化）した後、可動型８７を矢印の如く上昇する。
【００７３】
（ｃ）において、可動型８７を上昇することで型開きした中子成形型８６のキャビティ８６ａ内から、アノード側電極拡散層１５に一体に成形した第１ガス通路用中子１０１を取り出す。
【００７４】
一方、図１２の工程と同様の工程で、酸化剤ガス通路８４・・・（図１１に示す）の第２ガス通路用中子１０５（図１４参照）をカソード側電極拡散層３５と一体に成形することができる。
なお、燃料ガス通路８３・・・の第１ガス通路用中子１０１及びアノード側電極拡散層１５と、酸化剤ガス通路８４・・・の第２ガス通路用中子１０５及びカソード側電極拡散層３５については図１４で詳説する。
【００７５】
図１３（ａ），（ｂ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第２工程図であり、冷却水通路８５・・・（図１１に示す）の冷却水通路用中子を成形する例について説明する。
（ａ）において、中子成形型９７を型締めした状態で、中子成形型９７のキャビティ９７ａ内に、溶融状態の水溶性ポリマーを矢印▲５▼の如く充填する。水溶性ポリマーを凝固させて冷却水通路用中子１１１を成形した後、可動型９７を矢印の如く上昇する。
【００７６】
（ｂ）において、可動型９７を上昇することで型開きした中子成形型９６のキャビティ９７ａ内から冷却水通路用中子１１１を取り出す。
なお、成形した冷却水通路８５・・・の冷却水通路用中子１１１については図１４で詳説する。
【００７７】
図１４は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）に使用する中子（第１、第２ガス通路用中子及び冷却水通路用中子）の斜視図である。
アノード側電極拡散層１５は、一端側に燃料ガス供給孔部１６ａ、冷却水供給孔部１８ａ及び酸化剤ガス供給孔部１７ａを備え、他端側に燃料ガス排出孔部１６ｂ、冷却水排出孔部１８ｂ及び酸化剤ガス排出孔部１７ｂを備える。
このアノード側電極拡散層１５に第１ガス通路用中子１０１が一体に成形されている。
【００７８】
すなわち、第１ガス通路用中子１０１は、燃料ガス供給孔部１６ａに燃料ガス供給孔中子１０２を備え、燃料ガス排出孔部１６ｂに燃料ガス排出孔中子１０３を備える。
これらの燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３に燃料ガス通路中子１０４を一体成形することで第１ガス通路用中子１０１を得る。なお、燃料ガス通路中子１０４はアノード側電極拡散層１５に一体に成形されている。
これにより、アノード側電極拡散層１５及び第１ガス通路用中子１０１を一体にまとめることができる。
【００７９】
カソード側電極拡散層３５は、一端側に燃料ガス供給孔部３６ａ、冷却水供給孔部３８ａ及び酸化剤ガス供給孔部３７ａを備え、他端側に燃料ガス排出孔部３６ｂ、冷却水排出孔部３８ｂ及び酸化剤ガス排出孔部３７ｂを備える。
このカソード側電極拡散層３５に第２ガス通路用中子１０５が一体に成形されている。
【００８０】
すなわち、第２ガス通路用中子１０５は、酸化剤ガス供給孔部３７ａに酸化剤ガス供給孔中子１０６を備え、酸化剤ガス排出孔部３７ｂに酸化剤ガス排出孔中子１０７を備える。
これらの酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７に酸化剤ガス通路中子１０８を一体成形することで第２ガス通路用中子１０５を得る。なお、酸化剤ガス通路中子１０８はカソード側電極拡散層３５に一体に成形されている。
これにより、カソード側電極拡散層３５及び第２ガス通路用中子１０５を一体にまとめることができる。
【００８１】
第１ガス通路用中子１０１及び第２ガス通路用中子１０５間に配置する冷却水通路用中子１１１は、冷却水通路中子１１２の一端側に冷却水供給孔中子１１３を一体形成するとともに、他端側に冷却水排出孔中子１１４を一体成形したものである。
この冷却水供給孔中子１１３を、アノード側電極拡散層１５及びカソード側電極拡散層３５のそれぞれの冷却水供給孔部１８ａ，３８ａに嵌め込むとともに、アノード側電極拡散層１５及びカソード側電極拡散層３５のそれぞれの冷却水排出孔部１８ｂ，３８ｂに嵌め込む。
【００８２】
同時に、アノード側電極拡散層１５側の燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３を、カソード側電極拡散層３５の燃料ガス供給孔部３６ａ及び燃料ガス排出孔部３６ｂにそれぞれ嵌め込む。
さらに、カソード側電極拡散層３５側の酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７を、アノード側電極拡散層１５の酸化剤ガス供給孔部１７ａ及び酸化剤ガス排出孔部１７ｂにそれぞれ嵌め込む。
【００８３】
これにより、冷却水供給孔中子１１３及び冷却水排出孔中子１１４のそれぞれの下端１１３ａ，１１４ａがアノード側電極拡散層１５と面一になる。また、冷却水供給孔中子１１３及び冷却水排出孔中子１１４のそれぞれの上端１１３，１１４ｂがカソード側電極拡散層３５と面一になる。
【００８４】
また、燃料ガス供給孔中子１０２及び燃料ガス排出孔中子１０３のそれぞれの上端１０２ａ，１０３ａがカソード側電極拡散層３５と面一になる。
さらに、酸化剤ガス供給孔中子１０６及び酸化剤ガス排出孔中子１０７のそれぞれの下端１０６ａ，１０７ａがアノード側電極拡散層１５と面一になる。
【００８５】
次に、図１５〜図１６に基づいてセパレータを成形する工程について説明する。
図１５（ａ），（ｂ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第３工程図である。
（ａ）において、金型１２０の固定型１２１に第１ガス通路用中子１０１及びアノード側電極拡散層１５をセットし、第１ガス通路用中子１０１に冷却水通路用中子１１１を矢印の如く載せる。
次に、冷却水通路用中子１１１に第２ガス通路用中子１０５及びカソード側電極拡散層３５を矢印の如く載せた後、可動型１２２を矢印の如く下降して金型１２０を型締めする。
【００８６】
ここで、図１４に示すように、第２ガス通路用中子１０５及びカソード側電極拡散層３５を、酸化剤ガス供給孔中子１０６（図１４に示す）及び酸化剤ガス排出孔中子１０７でキャビティ面１２３ａに支えることができる。
また、冷却水通路用中子１１１を、冷却水供給孔中子１１３（図１４に示す）及び冷却水排出孔中子１１４でキャビティ１２３ａ面に支えることができる。
【００８７】
このように、第２ガス通路用中子１０５を酸化剤ガス供給孔中子１０６や酸化剤ガス排出孔中子１０７でキャビティ１２３内に配置するとともに、冷却水通路用中子１１１を冷却水供給孔中子１１３及び冷却水排出孔中子１１４でキャビティ１２３内に配置することができる。
よって、第２ガス通路用中子１０５や冷却水通路用中子１１１をキャビティ１２３内に配置するために通常必要とされるケレンなどの支え部材を不要にすることができる。
【００８８】
ケレンなどの支え部材を備えた場合には、キャビティ１２３内に樹脂を充填してセパレータを成形した後、ケレンなどの支え部材の部分がセパレータに隙間として残る虞がある。
その場合、残った隙間をシリコン剤などのシール剤で塞ぐ必要があるが、第３実施形態によればその必要はない。
【００８９】
（ｂ）において、金型１２０を型締めすることで、第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１を金型１２０のキャビティ１２３内に配置する。第１ガス通路用中子１０１及びキャビティ面１２３ａ間の隙間にアノード側電極拡散層１５を配置するとともに、第２ガス通路用中子１０５及びキャビティ面１２３ｂ間の隙間にカソード側電極拡散層３５を配置する。
この状態で、キャビティ１２３内に溶融樹脂を矢印▲６▼の如く充填する。
【００９０】
図１６（ａ）〜（ｃ）は本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第４工程図である。
（ａ）において、充填した溶融樹脂を凝固させてセパレータ８２を中子１００（第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１）、アノード側電極拡散層１５及びカソード電極拡散層３５と一体形成した後、可動型を上昇して金型１２０を型開きする。
型開きした後、セパレータ８２、中子１００、アノード側電極拡散層１５及びカソード電極拡散層３５をキャビティ１２３内から取り出す。
【００９１】
（ｂ）において、セパレータ８２、中子１００、アノード側電極拡散層１５及びカソード電極拡散層３５を、水槽１２５に蓄えた水１２６中に漬ける。
これにより、中子１００を水１２６で溶かすことにより、セパレータ８２内から溶出する。
このように、中子１００を水溶性ポリマーで成形することで、中子１００を水１２６で溶出することができる。このため、中子１００を溶出する設備を簡単にすることができるので、設備費を抑えて、コスト低減を図ることができる。
【００９２】
（ｃ）において、セパレータ８２内から第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１（（ｂ）に示す）を溶出することで、セパレータ８２に燃料ガス通路８３・・・、冷却水通路８５・・・及び酸化剤ガス通路８４・・・を開けることができる。
この状態で、水槽１２５内からセパレータ８２、アノード側電極拡散層１５及びカソード側電極拡散層３５を取り出すことにより、アノード側電極拡散層１５とカソード側電極拡散層３５間に一体形成したセパレータ８２を得る。
なお、このセパレータ８２は、図１１に示すセパレータ８２を反転した状態で示す。
【００９３】
以上説明した第３実施形態によれば、第１実施形態と同様の効果を得ることができる。すなわち、第３実施形態によれば、中子１００を水溶性ポリマーで形成し、この中子１００でセパレータ８２に燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を成形した。
これにより、セパレータ８２の成形後に中子１００を水１２６で溶出することで、燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を開けることができる。
【００９４】
このように、セパレータ８２内の中子１００を水１２６で溶出することができるので、セパレータ８２に燃料ガス通路８３・・・及び酸化剤ガス通路８４・・・を簡単に形成することができる。
【００９５】
さらに、セパレータ８２をアノード側電極拡散層１５及びカソード電極拡散層３５と一体形成した。これにより、セパレータ８２とアノード側電極拡散層１５との間の電気的な接触抵抗を抑えることができるとともに、セパレータ８２とカソード電極拡散層３５との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【００９６】
加えて、第３実施形態によれば、水溶性ポリマーの中子１００を利用してセパレータ８２内に冷却水通路８５・・・を形成することにした。セパレータ８２内に冷却水通路８５・・・を形成することができるので、従来技術のように一対のセパレータを重ね合わせて冷却水通路を形成する必要はない。
【００９７】
このように、従来必要とされていた一対のセパレータを一体成形することができるので、従来技術のように一対のセパレータ間に発生する電気的な接触抵抗を抑えることができる。
このように、接触抵抗を抑えることで、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができる。
【００９８】
次に、第３実施形態の抵抗過電圧を表２に基づいて説明する。
【００９９】
【表２】

【０１００】
第２比較例は、第１セパレータと第２セパレータとを一体化しないで、第１セパレータに第２セパレータを合わせたものである。
第２実施例は、セパレータを一体化した第３実施形態のものである。
【０１０１】
第２比較例と第２実施例との抵抗過電圧を以下の条件で測定した。
すなわち、セルモジュールの温度を８０℃に設定し、アノードガス（燃料ガス）として純Ｈ_２を供給するとともに、カソードガス（酸化剤ガス）として空気を供給した。
なお、アノード側の燃料ガス温度を８０℃、カソード側の酸化剤ガス温度を８０℃とし、アノード側の燃料ガス圧力を５０ｋＰａ、カソード側の酸化剤ガス圧力を１００ｋＰａとした。この条件下において、電流密度が０．８８３Ａ／ｃｍ^２の電流を流した。
【０１０２】
この結果、第２実施例の抵抗過電圧を、第２比較例の抵抗過電圧と比較して、１セルモジュール当たり０．０２７Ｖ減らすことができた。
よって、第２実施例（第３実施形態）のように、セパレータを一体化することにより、抵抗過電圧を減らして燃料電池の出力低下を防ぐことができることが分かる。
【０１０３】
次に、第４実施形態について説明する。
第３実施形態では、図１４に示すように、第１ガス通路用中子１０１をアノード側電極拡散層１５と一体に成形し、第２ガス通路用中子１０５カソード側電極拡散層３５と一体に成形した例について説明したが、これに限らないで、第１ガス通路用中子１０１をアノード側電極拡散層１５から切り離して成形し、第２ガス通路用中子１０５カソード側電極拡散層３５から切り離して成形することも可能である。
【０１０４】
この場合、図１５に示す金型１２０のキャビティ１２３内に、先ず、アノード側電極拡散層１５を配置し、アノード側電極拡散層１５に第１ガス通路用中子１０１を載せる。この第１ガス通路用中子１０１に冷却水通路用中子１１１を載せ、冷却水通路用中子１１１に第２ガス通路用中子１０５を載せた後、第２ガス通路用中子１０５にカソード側電極拡散層３５を載せる。
【０１０５】
この状態で金型１２０を型閉めすることにより、第３実施形態の図１５（ｂ）と同様に、第１、第２ガス通路用中子１０１，１０５及び冷却水通路用中子１１１、アノード側電極拡散層１５及びカソード側電極拡散層３５をキャビティ１２３内にセットすることができる。
よって、第４実施形態においても、第３実施形態と同様の効果を得ることができる。
【０１０６】
加えて、第４実施形態の燃料電池用セパレータの製造方法によれば、第１ガス通路用中子１０１をアノード側電極拡散層１５と個別に成形することができ、かつ第２ガス通路用中子１０５をカソード側電極拡散層３５と個別に成形することができる。
これにより、第１、第２ガス通路用中子１０１，１０５の成形方法を第３、第４実施形態のうちのいずれか一方から適宜選択することができるので、設計の自由度を高めることができる。
【０１０７】
なお、前記実施形態では、電解質膜１２として固体高分子電解質を使用した固体高分子型燃料電池１０，８０について説明したが、これに限らないで、その他の燃料電池に適用することも可能である。
【０１０８】
また、前記第１、第２実施形態では、第１、第２セパレータ２０，４０を射出成形方法で成形する例について説明したが、これに限らないで、例えば加熱プレス成形方法やトランスファー成形方法で成形することも可能である。
トランスファー成形装置とは、成形材料をキャビティとは別のポット部に１ショット分入れ、プランジャーによって溶融状態の材料をキャビティに移送して成形する方法である。
【０１０９】
加熱プレス成形方法で第１、第２セパレータ２０，４０を成形する際には、第１、第２セパレータ２０，４０を構成する樹脂としては、一例として耐酸性を備えた熱硬化性樹脂に、天然黒鉛、人造黒鉛、ケッチェンブラック、アセチレンブラックなどを単独或いは混合配合し、炭素材料を６０〜９０ｗｔ％含んだ樹脂組成物が該当する。
耐酸性の有する熱硬化性樹脂としては、例えばフェノール、ビニルエステルなどが該当するが、これに限定するものではない。
【０１１０】
【発明の効果】
本発明は上記構成により次の効果を発揮する。
請求項１は、ガス通路を形成するための中子を水溶性ポリマーで形成し、セパレータの成形後に中子を水で溶出することで、ガス通路を形成することができる。
このように、セパレータ内の中子を水で溶出することができるので、セパレータにガス通路を簡単に形成することができ、セパレータを簡単に製造することができる。
【０１１１】
また、セパレータを電極拡散層と一体に形成することにした。これにより、セパレータと電極拡散層との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【０１１２】
請求項２は、ガス通路を形成するためのガス通路用中子を水溶性ポリマーで形成し、セパレータの成形後にガス通路用中子を水で溶出することで、ガス通路を形成することができる。
このように、セパレータ内のガス通路用中子を水で溶出することができるので、セパレータにガス通路を簡単に形成することができ、セパレータを簡単に製造することができる。
【０１１３】
また、セパレータを電極拡散層と一体に形成することにした。これにより、セパレータと電極拡散層との間の電気的な接触抵抗を抑えることができるので、燃料電池の出力低下を防ぐことができる。
【０１１４】
さらに、冷却水通路用中子を水溶性ポリマーで形成し、セパレータの成形後に冷却水通路用中子を水で溶出することで、セパレータ内に冷却水通路を形成することにした。セパレータ内に冷却水通路を形成することができるので、一対のセパレータを重ね合わせて冷却水通路を形成する必要はない。
このように、一対のセパレータを重ね合わせる必要がないので、従来技術のように一対のセパレータ間に発生する電気的な接触抵抗をなくして、燃料電池の出力低下を防ぐことができる。
【図面の簡単な説明】
【図１】本発明に係る燃料電池用セパレータ（第１実施形態）を備えた燃料電池の分解斜視図
【図２】図１の２−２線断面図
【図３】図１の３−３線断面図
【図４】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第１工程図
【図５】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）に使用する中子の斜視図
【図６】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第２工程図
【図７】本発明に係る燃料電池用セパレータの製造方法（第１実施形態）を説明する第３工程図
【図８】図１の８−８線断面図
【図９】本発明に係る燃料電池用セパレータの製造方法（第２実施形態）を説明する工程図
【図１０】本発明に係る燃料電池用セパレータ（第３実施形態）を備えた燃料電池の分解斜視図
【図１１】図１０の１１−１１線断面図
【図１２】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第１工程図
【図１３】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第２工程図
【図１４】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）に使用する中子（第１、第２ガス通路用中子及び冷却水通路用中子）の斜視図
【図１５】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第３工程図
【図１６】本発明に係る燃料電池用セパレータの製造方法（第３実施形態）を説明する第４工程図
【図１７】従来の燃料電池を示す分解斜視図
【符号の説明】
１０，８０…燃料電池、１５…アノード側電極拡散層（電極拡散層）、２０…第１セパレータ（燃料電池用セパレータ）、２０ｂ…燃料ガス通路形成面（セパレータの表面）、２６，８３…燃料ガス通路（ガス通路）、３０，８５…冷却水通路、３５…カソード側電極拡散層（電極拡散層）、４０…第２セパレータ（燃料電池用セパレータ）、４０ｂ…酸化剤ガス通路形成面、４６，８４…酸化剤ガス通路（ガス通路）、５０，１００…中子、６０，１２０…金型、６３，１２３…キャビティ、６３ａ，６３ｂ，１２３ａ，１２３ｂ…キャビティ面、６６，１２６…水、８２…セパレータ（燃料電池用セパレータ）、８２ｂ…酸化剤ガス通路形成面（セパレータの両面の他方）、１０１…第１ガス通路用中子、１０５…第２ガス通路用中子、１１１…冷却水通路用中子、８２ａ…燃料ガス通路形成面（セパレータの両面の一方）。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a fuel cell separator that constitutes a cell module by attaching an anode electrode and a cathode electrode to an electrolyte membrane and sandwiching them from both sides.
[0002]
[Prior art]
A fuel cell is a cell that can obtain electricity in the process of obtaining water by reacting hydrogen and oxygen using the reverse principle of electrolysis of water. Generally, fuel gas is replaced by hydrogen, and air and oxidizing gas are replaced by oxygen. Therefore, the terms fuel gas, air, and oxidizing gas are often used.
[0003]
As such a fuel cell, for example, Japanese Patent Application Laid-Open No. 2000-123848, “Fuel Cell” is known. The fuel cell will be described with reference to FIG.
FIG. 17 is an exploded perspective view showing a conventional fuel cell.
The fuel cell 200 constitutes a cell module by attaching an anode electrode 202 and a cathode electrode 203 to an electrolyte membrane 201 and sandwiching them between a first separator 206 and a second separator 207 via gaskets 204 and 205.
[0004]
Specifically, a first flow path 208 serving as a fuel gas flow path is formed on a surface 206a of the first separator 206, and a second flow path 209 serving as an oxidant gas flow path is formed on a surface 207a of the second separator 207. The fuel cell and the oxidizing gas are formed so as to face the central electrolyte membrane 201, respectively.
[0005]
Since the electric output obtained by one cell module is extremely small, a desired electric output is obtained by stacking a large number of such cell modules. Therefore, the first and second separators 206 and 207 are called "separators" because they are separation members for preventing fuel gas and oxidizing gas from leaking to adjacent cells.
[0006]
The first separator 206 has a flow path 208 for fuel gas on the surface 206a, and the second separator 207 has a flow path 209 for oxidizing gas on the surface 207a. It is necessary to make contact with the cathode-side electrode 203. For this purpose, it is necessary to form a large number of extremely shallow grooves in the flow paths 208 and 209.
[0007]
The first and second separators 206 and 207 have a fuel gas supply hole 210a and an oxidant gas supply hole 211a at their upper portions for supplying a fuel gas or an oxidant gas to the channels 208 and 209, respectively. A lower portion is provided with a fuel gas discharge hole portion 210b and an oxidizing gas discharge hole portion 211b, and a cooling water supply hole portion 212a for passing cooling water is provided at an upper portion, and a cooling water discharge hole portion 212b is provided at a lower portion. Prepare for.
[0008]
[Problems to be solved by the invention]
The cooling water supply hole 212a and the cooling water discharge hole 212b are respectively connected to a cooling water passage (not shown).
The cooling water passage, for example, forms a cooling water passage groove on each of the surface on the back side of the surface 206a of the first separator 206 and the surface on the back side of the surface 207a of the second separator 207. It is formed by matching cooling water passage grooves provided in separators of adjacent cells.
[0009]
When the cooling water passage is formed by combining the separators as described above, a sealing material for preventing leakage of the cooling water is required at a portion where the separators are joined, and the thickness, shape, material, and the like of the sealing material are taken into consideration. There must be.
[0010]
In addition, a gas passage groove is provided on one surface of the first separator 206 or the second separator 207, and a cooling water passage groove is provided on the other surface, so that molding of each groove becomes difficult.
Further, the electrical contact resistance between the separators increases in order to match the separators, and the voltage of each cell drops due to the contact resistance, so that the output of the fuel cell may decrease.
[0011]
Therefore, an object of the present invention is to provide a method of manufacturing a separator for a fuel cell, in which the separator can be easily manufactured and a decrease in the output of the fuel cell can be suppressed.
[0012]
[Means for Solving the Problems]
To achieve the above object, a first aspect of the present invention provides a step of forming a core for forming a gas passage with a water-soluble polymer, disposing the core in a cavity of a mold, and forming a core and a cavity surface. A step of arranging the electrode diffusion layer in the gap between, and a step of filling the cavity with a molten resin, and forming a separator solidified from the molten resin with the core and the electrode diffusion layer and then from the inside of the cavity. A method for manufacturing a fuel cell separator is constituted by a step of taking out the core and a step of forming a gas passage on the surface of the separator with the separator and the electrode diffusion layer by eluting the core from the separator with water.
[0013]
A gas passage can be formed by forming a core for forming a gas passage with a water-soluble polymer and eluting the core with water after forming the separator.
As described above, since the core in the separator can be eluted with water, a gas passage can be easily formed in the separator.
[0014]
Here, a normal fuel cell includes an anode-side electrode diffusion layer between the anode-side electrode and the separator, and includes a cathode-side electrode diffusion layer between the cathode-side electrode and the separator.
Thus, the electrical contact resistance between the separator and the anode-side electrode diffusion layer and the electrical resistance between the separator and the cathode-side electrode diffusion layer can be adjusted to match the anode-side electrode diffusion layer with the separator and the cathode-side electrode diffusion layer with the separator. It is conceivable that the actual contact resistance increases. The voltage of the fuel cell drops due to this contact resistance, and the output of the fuel cell may be reduced.
[0015]
Therefore, in claim 1, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between the separator and the electrode diffusion layer can be suppressed.
[0016]
Claim 2 is a step of forming a gas passage core and a cooling water passage core for forming a gas passage and a cooling water passage with a water-soluble polymer, and placing the gas passage core on a cavity surface of a mold. A step of disposing the electrode diffusion layer in the gap between the gas passage core and the cavity surface by arranging the cooling water passage core at a predetermined distance from the gas passage core, and A step of filling the molten resin in the cavity, and a step of forming the solidified separator of the molten resin, forming the core for the gas passage, the core for the cooling water passage and the electrode diffusion layer, and then removing the separator from the cavity, The gas passage core and the cooling water passage core are eluted with water from the separator, thereby forming a gas passage on the surface of the separator with the separator and the electrode diffusion layer, and forming a cooling water passage in the separator. It constitutes a method of manufacturing a fuel cell separator and a step of.
[0017]
A gas passage can be formed by forming a gas passage core for forming a gas passage from a water-soluble polymer and eluting the gas passage core with water after forming the separator.
Thus, the gas passage core in the separator can be eluted with water, so that the gas passage can be easily formed in the separator.
Further, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between the separator and the electrode diffusion layer can be suppressed.
[0018]
Here, in a normal separator, a pair of separators are overlapped to form a cooling water passage by combining a cooling water passage groove of one separator with a cooling water passage groove of the other separator.
As described above, it is conceivable that the electrical contact resistance between the pair of separators is increased by overlapping the pair of separators. The voltage of the fuel cell drops due to this contact resistance, and the output of the fuel cell may be reduced.
[0019]
Therefore, in claim 2, a cooling water passage is formed in the separator by forming the cooling water core with a water-soluble polymer and eluting the cooling water core with water after the separator is formed. Since the cooling water passage can be formed in the separator, it is not necessary to form a cooling water passage by overlapping a pair of separators.
As described above, since it is not necessary to overlap the pair of separators, electrical contact resistance generated between the pair of separators can be eliminated.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals.
FIG. 1 is an exploded perspective view of a fuel cell provided with a fuel cell separator (first embodiment) according to the present invention.
As an example, the fuel cell 10 uses a solid polymer electrolyte for the electrolyte membrane 12, attaches the anode 13 and the cathode 14 to the electrolyte membrane 12, and provides the anode-side electrode diffusion layer 15 on the anode 13 side. The cell module 11 is formed by combining the first separator (separator) 20 with the second separator (separator) 40 via the cathode-side electrode diffusion layer 35 on the cathode-side electrode 14 side. Is a polymer electrolyte fuel cell in which a large number of are stacked.
[0021]
When the adjacent cell modules 11 and 11 are stacked, the first separator 20 forming one cell module 11 and the second separator 40 forming the other cell module 11 are cooled by cooling the respective separators 20 and 40. The water passage forming surfaces 20a and 40a are combined.
[0022]
Thereby, cooling water passages 30 (shown in FIG. 8) are formed by the cooling water passage grooves 21 of the first separator 20 and the cooling water passage grooves 41 of the second separator 40.
The cooling water passages 30 communicate with cooling water supply holes 22a, 42a at the center of the upper ends of the first and second separators 20, 30, and at the center of the lower ends of the first and second separators 20, 40. The cooling water discharge holes 22b and 42b communicate with each other.
[0023]
The first separator 20 is formed by integrally forming (that is, integrating) the anode-side electrode diffusion layer (electrode diffusion layer) 15 on the side of the fuel gas passage forming surface (the surface of the separator) 20b, thereby forming the fuel gas passage forming surface 20b. (Shown in FIG. 2) are formed on the fuel gas passage groove (gas passage) 23.
The fuel gas passage grooves 23 communicate with the fuel gas supply holes 24a, 44a on the upper left side of the first and second separators 20, 40, and on the lower right side of the first and second separators 20, 40. The fuel gas discharge holes 24b and 44b communicate with each other.
[0024]
In the second separator 40, the cathode-side electrode diffusion layer (electrode diffusion layer) 35 is integrally formed (that is, integrated) with the oxidizing gas passage forming surface (the surface of the separator) 40b, thereby forming the oxidizing gas passage. The oxidizing gas passages (gas passages) 46 shown in FIG. 8 are formed on the surface 40b side.
The oxidizing gas passages 46 communicate with the oxidizing gas supply holes 25a, 45a on the upper right sides of the first and second separators 20, 40, and the lower left sides of the first and second separators 20, 40. Oxidant gas discharge holes 25b, 25b.
[0025]
Examples of the resin constituting the first and second separators 20 and 40 include, for example, a thermoplastic resin having acid resistance, natural graphite, artificial graphite, Ketjen black, acetylene black, etc., alone or in a mixture. Corresponds to a resin composition containing 60 to 90 wt%.
[0026]
Examples of the thermoplastic resin having acid resistance include ethylene / vinyl acetate (vinyl acetate) copolymer, ethylene / ethyl acrylate copolymer, linear low-density polyethylene, polyphenylene sulfide, and modified polyphenylene oxide. However, the present invention is not limited to this.
[0027]
FIG. 2 is a sectional view taken along line 2-2 of FIG.
The first separator 20 is a member formed in a substantially rectangular shape as shown in FIG. 1, and has a large number of fuel gas passage forming grooves 23 on a fuel gas passage forming surface 20b. Are integrally provided with the anode-side electrode diffusion layer 15, so that the fuel gas passage grooves 23 and the fuel gas passages 26 are formed by the anode-side electrode diffusion layer 15, and the cooling water passage formation surface 20a is cooled. There are many grooves 21 for water passages.
[0028]
FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. The anode-side electrode diffusion layer 15 is integrally formed on the side of the fuel gas passage forming surface 20b of the first separator 20, so that the fuel gas passage groove 23 and the anode-side A state in which a fuel gas passage 26 is formed by the electrode diffusion layer 15 and a fuel gas supply hole 24a on the upper left side of the upper end of the first separator 20 communicates with the fuel gas passage 26 is shown.
[0029]
Next, a method for manufacturing the fuel cell separator will be described with reference to FIGS.
First, a process of molding the core 50 for forming the fuel gas passage 26 and the cooling water passage groove 21 with a water-soluble polymer will be described with reference to FIGS.
FIGS. 4A to 4C are first process diagrams illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
In (a), after setting the anode-side electrode diffusion layer 15 on the movable mold 57 in a state where the core forming mold 56 is opened, the movable mold 57 is lowered toward the fixed mold 58 as indicated by an arrow, and the core is lowered. The mold 56 is clamped.
[0030]
In (b), the cavity 56a of the core mold 56 is filled with a water-soluble polymer in a molten state as shown by the arrow (1). After the water-soluble polymer is solidified and the core 5 is formed integrally with the anode-side electrode diffusion layer 15 (that is, integrated), the movable mold 57 is raised as shown by the arrow.
[0031]
Examples of the water-soluble polymer include, but are not limited to, polyacrylamide, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyvinyl alcohol, and the like. That is, any water-soluble polymer that can be used as a core and has water solubility may be used.
[0032]
In (c), the core 50 integrally formed with the anode-side electrode diffusion layer 15 is taken out from the cavity 56a of the core forming die 56 opened by raising the movable die 57.
[0033]
FIG. 5 is a perspective view of a core used in the method for manufacturing a fuel cell separator (first embodiment) according to the present invention, and illustrates an anode-side electrode diffusion layer 15 taken out of a cavity 56a (shown in FIG. 4). The core 50 integrally formed with the anode-side electrode diffusion layer 15 is shown.
Note that FIG. 5 shows a state in which the core 50 is directed upward so that the shape of the core 50 can be easily understood.
[0034]
The anode-side electrode diffusion layer 15 includes a fuel gas supply hole 16a, a cooling water supply hole 18a, and an oxidizing gas supply hole 17a on one end, and a fuel gas discharge hole 16b and a cooling water discharge hole on the other end. And an oxidizing gas discharge hole 17b.
The fuel gas supply hole 16a, the cooling water supply hole 18a, and the oxidant gas supply hole 17a are provided with a fuel gas supply hole core 51a, a cooling water supply hole core 52a, and an oxidant gas supply hole core 53a.
[0035]
Further, a fuel gas discharge hole core 51b, a cooling water discharge hole core 52b, and an oxidant gas discharge hole core 53b are provided in the fuel gas discharge hole 16b, the cooling water discharge hole 18b, and the oxidizing gas discharge hole 17b. Prepare.
The fuel gas passage core 54 is formed integrally with the anode electrode diffusion layer 15, the supply side 54 a of the fuel gas passage core 54 is connected to the fuel gas supply hole core 51 a, and the fuel gas passage core 54 is discharged. The side 54b is connected to the fuel gas discharge hole core 51b.
[0036]
Thus, the anode-side electrode diffusion layer 15, the fuel gas supply hole core 51a, the cooling water supply hole core 52a, the oxidizing gas supply hole core 53a, the fuel gas discharge hole core 51b, and the cooling water discharge hole core 52b The oxidant gas discharge hole core 53b and the fuel gas passage core 54 can be integrated.
The fuel gas supply hole core 51a, the cooling water supply hole core 52a, the oxidant gas supply hole core 53a, the fuel gas discharge hole core 51b, the cooling water discharge hole core 52b, and the oxidant gas discharge hole core The core 53 b and the fuel gas passage core 54 constitute a core 50.
[0037]
When the core 50 and the anode-side electrode diffusion layer 15 are set in the mold cavity, the tip 51c of the fuel gas supply hole core 51a, the tip 52c of the cooling water supply hole core 52a, the oxidant gas supply The tip 53c of the hole core 53a, the tip 51e of the fuel gas discharge hole core 51b, the tip 52e of the cooling water discharge hole core 52b, and the tip 53e of the oxidant gas discharge hole core 53b are placed on the cavity surface of the mold.
[0038]
Next, a process of forming the first separator will be described with reference to FIGS.
FIGS. 6A and 6B are second process diagrams illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
6A, the core 50 and the anode-side electrode diffusion layer 16 are set on the fixed mold 61 of the mold 60, and the movable mold 62 is lowered as indicated by the arrow to clamp the mold 60.
[0039]
As described with reference to FIG. 5, the core 50 includes a tip 51c of the fuel gas supply hole core 51a, a tip 52c of the cooling water supply hole core 52a, a tip 53c of the oxidant gas supply hole core 53a, and fuel gas discharge. The tip 51e of the hole core 51b, the tip 52e of the cooling water discharge hole core 52b, and the tip 53e of the oxidizing gas discharge hole core 53b are placed on the cavity surface 63a of the mold 60.
Thereby, the core 50 and the anode-side electrode diffusion layer 15 can be set on the cavity surface 63a of the fixed mold 61.
[0040]
As described above, the core 50 can be arranged in the cavity 63 using the supply hole cores 51a, 52a, 53a and the discharge hole cores 51b, 52b, 53b. It is possible to eliminate the need for a support member such as kerosene which is normally required to be disposed in the inside of the housing 63.
[0041]
When a support member such as kerosene is provided, after the cavity 63 is filled with a resin to form a separator, there is a possibility that a portion of the support member such as kerosene may remain as a gap in the separator.
In that case, it is necessary to close the remaining gap with a sealant such as a silicone agent, but according to the first embodiment, this is not necessary.
[0042]
In (b), by clamping the mold 60, the core 50 is arranged in the cavity 63 of the mold 60, and the anode-side electrode diffusion layer 15 is arranged in the gap between the core 50 and the cavity surface 63b. I do.
In this state, the cavity 63 is filled with the molten resin as shown by the arrow (2).
[0043]
FIGS. 7A to 7C are third process diagrams illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
In (a), after the molten resin in the cavity is solidified to form the first separator 20 integrally with the core 50 and the anode-side electrode diffusion layer 15, the movable mold 62 is raised to open the mold 60. Then, the first separator 20, the core 50 and the anode-side electrode diffusion layer 15 are taken out from the cavity 63.
[0044]
In (b), the first separator 20, the core 50, and the anode-side electrode diffusion layer 15 are immersed in water 66 stored in a water tank 65. As a result, the core 50 is dissolved in the water, and the core 50 is eluted from the first separator 20.
By molding the core 50 with a water-soluble polymer, the core 50 can be eluted with water. For this reason, since the equipment for dissolving the core 50 can be simplified, the equipment cost can be suppressed and the cost can be reduced.
[0045]
In (c), the first separator 20 and the anode-side electrode diffusion layer 15 are taken out of the water tank 65. The fuel gas passage 26 is formed in the taken-out first separator 20 by the core 50 (shown in (b)) being eluted.
The cooling water passage groove 21 of the first separator 20 can be formed by the cavity surface 63a (shown in (a)) of the fixed die 61.
Thereby, the first separator 20 formed integrally with the anode-side electrode diffusion layer 15 is obtained.
[0046]
The second separator 40 formed integrally with the cathode-side electrode diffusion layer 35 shown in FIG. 1 can be obtained in the same manner as the first separator 2 by sequentially performing the same steps as those in FIGS. it can.
The state where the first separator 20 integrally formed on the anode-side electrode diffusion layer 15 and the second separator 40 integrally formed on the cathode-side electrode diffusion layer 35 thus obtained are combined is shown in the following figure.
[0047]
FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 1. The first separator 20 formed integrally with the anode-side electrode diffusion layer 15 and the second separator 40 formed integrally with the cathode-side electrode diffusion layer 35 are shown in FIG. The state where the separators 20 and 40 are combined at the cooling water passage forming surfaces 20a and 40a is shown.
[0048]
By combining the first and second separators 20 and 40 at the respective cooling water passage forming surfaces 20a and 40a, the cooling water passage grooves 21 of the first separator 20 and the cooling water passage grooves 41 of the second separator 40 are formed. .. Can form the cooling water passages 30.
[0049]
Also, by integrally molding the first separator 20 with the anode-side electrode diffusion layer 15, the fuel gas passages 26 can be formed on the fuel gas passage formation surface 20b. Further, by integrally molding the second separator 40 with the cathode-side electrode diffusion layer 35, the oxidizing gas passages 46 can be formed on the oxidizing gas passage forming surface 40b.
[0050]
As described above, according to the first embodiment, the core 50 is formed of a water-soluble polymer, and the core 50 is used to form the fuel gas passages 26 in the first separator 20. Thereby, after the core 50 is eluted with the water 66 after the formation of the first separator 20, the fuel gas passages 26 can be opened.
[0051]
Similarly to the first separator 20, the core of the second separator 40 was formed of a water-soluble polymer, and the oxidant gas passages 46 were formed in the second separator 40 with the core. Thus, the core is eluted with the water 66 after the formation of the second separator 40, so that the fuel gas passages 46 can be opened.
Since the cores in the first and second separators 20 and 40 can be eluted with the water 66 in this manner, the fuel gas passages 26. Can easily be formed.
[0052]
Further, the first and second separators 20 and 40 were formed integrally with the anode-side electrode diffusion layer 15 and the cathode electrode diffusion layer 35, respectively. Thereby, the electrical contact resistance between the first separator 20 and the anode-side electrode diffusion layer 15 can be suppressed, and the electrical contact resistance between the second separator 40 and the cathode electrode diffusion layer 35 can be reduced. Can be suppressed.
As described above, by suppressing the contact resistance, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from lowering.
[0053]
Next, the resistance overvoltage of the first embodiment will be described based on Table 1.
[0054]
[Table 1]

[0055]
In the first comparative example, the first separator and the anode-side electrode diffusion layer were not integrated, and the first separator was brought into contact with the anode-side electrode diffusion layer.
The first example is of the first embodiment in which the first separator and the anode-side electrode diffusion layer are integrated.
[0056]
The resistance overvoltages of the first comparative example and the first example were measured under the following conditions.
That is, the temperature of the cell module is set to 80 ° C., and pure H is used as the anode gas (fuel gas). ₂ And air was supplied as a cathode gas (oxidant gas).
The fuel gas temperature on the anode side was 80 ° C., the oxidant gas temperature on the cathode side was 80 ° C., the fuel gas pressure on the anode side was 50 kPa, and the oxidant gas pressure on the cathode side was 100 kPa. Under these conditions, the current density is 0.883 A / cm ² Was passed.
[0057]
As a result, the resistance overvoltage of the first example could be reduced by 0.014 V per cell module as compared with the resistance overvoltage of the first comparative example.
Therefore, as in the first example (first embodiment), by integrating the first separator and the anode-side electrode diffusion layer, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from lowering. .
[0058]
Next, a second embodiment and a fourth embodiment will be described. In the second and third embodiments, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
FIGS. 9A to 9C are process diagrams illustrating a method (second embodiment) of manufacturing a fuel cell separator according to the present invention.
In (a), with the core mold 76 clamped, the cavity 76a of the core mold 76 is filled with a water-soluble polymer in a molten state as shown by the arrow (3). After solidifying the water-soluble polymer to form the core 50, the movable mold 77 is moved up as shown by the arrow.
[0059]
In (b), the core 50 is taken out from the cavity 76a of the core mold 76 opened by raising the movable mold 77.
In (c), the core 50 is set on the fixed die 61 of the mold 60, and after setting the core 50, the anode-side electrode diffusion layer 15 is placed on the core 50 as shown by an arrow. After setting the core 50 and the anode-side electrode diffusion layer 15 in the cavity 63 in this manner, the movable mold 62 is lowered as indicated by the arrow, and the mold 60 is clamped.
[0060]
Thereby, the state of FIG. 6B of the first embodiment is obtained. Hereinafter, by sequentially repeating the same steps as in the first embodiment, the first separator 20 integrally formed with the anode-side electrode diffusion layer 15 shown in FIG. 1 can be obtained.
Further, the second separator 40 integrally formed with the cathode-side electrode diffusion layer 35 shown in FIG. 1 can be obtained by the same steps as those in FIG.
[0061]
According to the second embodiment, the same effects as those of the first embodiment can be obtained.
Further, according to the method for manufacturing a fuel cell separator of the second embodiment, the core 50 can be formed separately from the anode-side electrode diffusion layer 15. Thereby, the molding method of the core 50 can be appropriately selected from either one of the first and second embodiments, so that the degree of freedom of design can be increased.
[0062]
Next, a third embodiment will be described with reference to FIGS.
FIG. 10 is an exploded perspective view of a fuel cell provided with the fuel cell separator (third embodiment) according to the present invention.
In the fuel cell 80, the anode (electrode) 13 and the cathode 14 are attached to the electrolyte membrane 12, the separator (fuel cell separator) 82 is combined with the anode 13 via the anode electrode diffusion layer 15, and the cathode The cell module 81 is configured by combining a separator 82 with the side electrode 14 via the cathode-side electrode diffusion layer 35.
[0063]
FIG. 11 is a sectional view taken along line 11-11 of FIG.
The separator 82 is formed by integrally forming the anode-side electrode diffusion layer 15 on the fuel gas passage forming surface (one of both surfaces of the separator) 82a, so that the fuel gas passage (gas) is formed on the fuel gas passage forming surface 82a. ) Are formed.
[0064]
The separator 82 is formed by integrally forming the cathode-side electrode diffusion layer 35 on the oxidizing gas passage forming surface (the other surface of both surfaces of the separator) 82b, thereby oxidizing the oxidizing gas passage forming surface 82b. A large number of agent gas passages (gas passages) 86 are formed.
Further, the separator 82 includes a number of cooling water passages 85 between the fuel gas passages 83 and the oxidizing gas passages 84.
[0065]
As the resin constituting the separator 82, as in the first embodiment, as an example, a natural graphite, artificial graphite, Ketjen black, acetylene black, or the like is used alone or in combination with an acid-resistant thermoplastic resin. A resin composition containing 60 to 90% by weight of the material corresponds to the resin composition.
[0066]
Examples of the thermoplastic resin having acid resistance include ethylene / vinyl acetate (vinyl acetate) copolymer, ethylene / ethyl acrylate copolymer, linear low-density polyethylene, polyphenylene sulfide, and modified polyphenylene oxide. However, the present invention is not limited to this.
[0067]
Returning to FIG. 10, the fuel gas supply holes 91a on the upper left side of the separator 82 communicate with the fuel gas passages 83... (Shown in FIG. 11), and the fuel gas discharge holes 91b on the lower right side of the separator 82. To communicate.
(See also FIG. 11). The oxidizing gas supply holes 92a on the upper right side of the separator 82 communicate with the oxidizing gas passages 84. Communicate.
(Shown in FIG. 11) communicates with a cooling water supply hole 93a at the center of the upper end of the separator 82, and communicates with a cooling water discharge hole 93b at the center of the lower end of the separator 82.
[0068]
That is, in the fuel cell separator 82 of the third embodiment, the cooling water passages 85 are formed between the fuel gas passages 83 and the oxidizing gas passages 84. The other configuration is the same as that of the first embodiment except that the first and second separators 20 and 40 are integrally formed.
As described above, by integrally molding the first and second separators 20 and 40, the electrical contact resistance generated between the pair of separators 20 and 40 is eliminated, and the output reduction of the fuel cell is more suitably prevented. Can be.
[0069]
Next, a method for manufacturing a fuel cell separator will be described with reference to FIGS.
First, a fuel gas passage 83, an oxidizing gas passage 84, and a cooling water passage 85 (shown in FIG. 11) are formed of a water-soluble polymer based on FIGS. The step of forming the child 100 (shown in FIG. 14) will be described.
The core 100 includes a first gas passage core, a second gas passage core, and a cooling water passage core. The first gas passage core, the second gas passage core, and the cooling water core. The manufacturing process of the passage core will be described below.
[0070]
The core 100 is formed of a water-soluble polymer as in the first embodiment. Examples of the water-soluble polymer include, but are not limited to, polyacrylamide, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyvinyl alcohol, and the like.
That is, any water-soluble polymer that can be used as a core and has water solubility may be used.
[0071]
12 (a) to 12 (c) are first process diagrams illustrating a method for manufacturing a fuel cell separator (third embodiment) according to the present invention, and show fuel gas passages 83 ... (shown in FIG. 11). An example of forming the first gas passage core will be described.
In (a), after setting the anode-side electrode diffusion layer 15 on the movable die 87 with the core forming die 86 opened, the movable die 87 is lowered toward the fixed die 88 as indicated by an arrow, and the core is lowered. The mold 86 is clamped.
[0072]
In (b), the cavity 86a of the core mold 86 is filled with a water-soluble polymer in a molten state as shown by an arrow (4). After the water-soluble polymer is solidified and the first gas passage core 101 is integrally formed (that is, integrated) with the anode-side electrode diffusion layer 15, the movable mold 87 is raised as shown by the arrow.
[0073]
In (c), the first gas passage core 101 integrally formed with the anode-side electrode diffusion layer 15 is taken out from the cavity 86a of the core forming die 86 opened by raising the movable die 87.
[0074]
On the other hand, in the same step as the step in FIG. 12, the core 105 for the second gas passage (see FIG. 14) of the oxidizing gas passages 84... Can be molded.
The first gas passage core 101 and the anode electrode diffusion layer 15 of the fuel gas passages 83... And the second gas passage core 105 and the cathode electrode diffusion layer of the oxidant gas passages 84. Details of 35 will be described in FIG.
[0075]
FIGS. 13 (a) and 13 (b) are second process diagrams illustrating a method (third embodiment) of manufacturing a fuel cell separator according to the present invention, and show cooling water passages 85... (Shown in FIG. 11). An example of molding the cooling water passage core will be described.
In (a), while the core mold 97 is clamped, the cavity 97a of the core mold 97 is filled with a water-soluble polymer in a molten state as shown by an arrow (5). After solidifying the water-soluble polymer to form the cooling water passage core 111, the movable mold 97 is raised as shown by the arrow.
[0076]
In (b), the core 111 for the cooling water passage is taken out from the cavity 97a of the core forming die 96 opened by raising the movable die 97.
The cooling water passage cores 111 of the formed cooling water passages 85... Will be described in detail with reference to FIG.
[0077]
FIG. 14 is a perspective view of cores (first and second gas passage cores and cooling water passage cores) used in the fuel cell separator manufacturing method (third embodiment) according to the present invention.
The anode-side electrode diffusion layer 15 includes a fuel gas supply hole 16a, a cooling water supply hole 18a, and an oxidizing gas supply hole 17a on one end, and a fuel gas discharge hole 16b and a cooling water discharge hole on the other end. And an oxidizing gas discharge hole 17b.
The first gas passage core 101 is formed integrally with the anode-side electrode diffusion layer 15.
[0078]
That is, the first gas passage core 101 includes the fuel gas supply hole core 102 in the fuel gas supply hole 16a and the fuel gas discharge hole core 103 in the fuel gas discharge hole 16b.
The first gas passage core 101 is obtained by integrally molding the fuel gas passage core 104 with the fuel gas supply hole core 102 and the fuel gas discharge hole core 103. Note that the fuel gas passage core 104 is formed integrally with the anode-side electrode diffusion layer 15.
Thereby, the anode-side electrode diffusion layer 15 and the first gas passage core 101 can be integrated.
[0079]
The cathode-side electrode diffusion layer 35 includes a fuel gas supply hole 36a, a cooling water supply hole 38a, and an oxidizing gas supply hole 37a on one end, and a fuel gas discharge hole 36b and a cooling water discharge hole on the other end. And an oxidizing gas exhaust hole 37b.
The second gas passage core 105 is formed integrally with the cathode-side electrode diffusion layer 35.
[0080]
That is, the second gas passage core 105 includes the oxidant gas supply hole core 106 in the oxidant gas supply hole 37a and the oxidant gas discharge hole core 107 in the oxidant gas discharge hole 37b.
The oxidizing gas passage core 108 is integrally formed with the oxidizing gas supply hole core 106 and the oxidizing gas discharge hole core 107 to obtain the second gas passage core 105. The oxidant gas passage core 108 is formed integrally with the cathode-side electrode diffusion layer 35.
Thus, the cathode-side electrode diffusion layer 35 and the second gas passage core 105 can be integrated.
[0081]
The cooling water passage core 111 disposed between the first gas passage core 101 and the second gas passage core 105 has a cooling water supply hole core 113 integrally formed at one end of the cooling water passage core 112. In addition, a cooling water discharge hole core 114 is integrally formed on the other end side.
The cooling water supply hole core 113 is fitted into the cooling water supply holes 18a and 38a of the anode-side electrode diffusion layer 15 and the cathode-side electrode diffusion layer 35, respectively. The cooling water discharge holes 18b and 38b of the layer 35 are fitted.
[0082]
At the same time, the fuel gas supply hole core 102 and the fuel gas discharge hole core 103 on the anode side electrode diffusion layer 15 side are fitted into the fuel gas supply hole portion 36a and the fuel gas discharge hole portion 36b of the cathode side electrode diffusion layer 35, respectively. Put in.
Further, the oxidizing gas supply hole core 106 and the oxidizing gas discharge hole core 107 on the cathode side electrode diffusion layer 35 side are connected to the oxidizing gas supply hole portion 17a and the oxidizing gas discharge hole portion of the anode side electrode diffusion layer 15. 17b.
[0083]
Thereby, the lower ends 113a and 114a of the cooling water supply hole core 113 and the cooling water discharge hole core 114 are flush with the anode-side electrode diffusion layer 15. The upper ends 113 and 114b of the cooling water supply hole core 113 and the cooling water discharge hole core 114 are flush with the cathode-side electrode diffusion layer 35.
[0084]
The upper ends 102 a and 103 a of the fuel gas supply hole core 102 and the fuel gas discharge hole core 103 are flush with the cathode-side electrode diffusion layer 35.
Further, the lower ends 106 a and 107 a of the oxidizing gas supply hole core 106 and the oxidizing gas discharge hole core 107 are flush with the anode-side electrode diffusion layer 15.
[0085]
Next, a process of forming the separator will be described with reference to FIGS.
FIGS. 15A and 15B are third process diagrams illustrating a method (third embodiment) of manufacturing a fuel cell separator according to the present invention.
In (a), the core 101 for the first gas passage and the anode-side electrode diffusion layer 15 are set on the fixed die 121 of the mold 120, and the core 111 for the cooling water passage is attached to the core 101 for the first gas passage by an arrow. Put it like.
Next, after the second gas passage core 105 and the cathode-side electrode diffusion layer 35 are placed on the cooling water passage core 111 as shown by the arrow, the movable mold 122 is lowered as shown by the arrow and the mold 120 is clamped. I do.
[0086]
Here, as shown in FIG. 14, the second gas passage core 105 and the cathode-side electrode diffusion layer 35 are connected to the oxidizing gas supply hole core 106 (shown in FIG. 14) and the oxidizing gas discharge hole core 107. Can be supported on the cavity surface 123a.
The cooling water passage core 111 can be supported on the surface of the cavity 123a by the cooling water supply hole core 113 (shown in FIG. 14) and the cooling water discharge hole core 114.
[0087]
As described above, the core 105 for the second gas passage is arranged in the cavity 123 by the core 106 for the oxidizing gas supply hole and the core 107 for the oxidizing gas discharge hole, and the core 111 for the cooling water passage is supplied with the cooling water. The hole core 113 and the cooling water discharge hole core 114 can be arranged in the cavity 123.
Therefore, it is possible to eliminate the need for a support member such as kerosene or the like that is normally required for disposing the second gas passage core 105 and the cooling water passage core 111 in the cavity 123.
[0088]
When a support member such as kerosene is provided, after the cavity 123 is filled with a resin to form a separator, a portion of the support member such as kerosene may remain as a gap in the separator.
In that case, it is necessary to close the remaining gap with a sealing agent such as a silicone agent, but according to the third embodiment, this is not necessary.
[0089]
In (b), the mold 120 is clamped to dispose the first and second gas passage cores 101 and 105 and the cooling water passage core 111 in the cavity 123 of the mold 120. The anode-side electrode diffusion layer 15 is disposed in the gap between the first gas passage core 101 and the cavity surface 123a, and the cathode-side electrode diffusion layer 35 is disposed in the gap between the second gas passage core 105 and the cavity surface 123b. Deploy.
In this state, the cavity 123 is filled with the molten resin as shown by the arrow (6).
[0090]
FIGS. 16A to 16C are fourth process diagrams illustrating a method (third embodiment) of manufacturing a fuel cell separator according to the present invention.
In (a), the filled molten resin is solidified to separate the separator 82 into the core 100 (the first and second gas passage cores 101 and 105 and the cooling water passage core 111), the anode-side electrode diffusion layer 15 and After being integrally formed with the cathode electrode diffusion layer 35, the movable mold is raised and the mold 120 is opened.
After opening the mold, the separator 82, the core 100, the anode-side electrode diffusion layer 15, and the cathode electrode diffusion layer 35 are taken out of the cavity 123.
[0091]
In (b), the separator 82, the core 100, the anode-side electrode diffusion layer 15, and the cathode electrode diffusion layer 35 are immersed in water 126 stored in a water tank 125.
As a result, the core 100 is dissolved in the water 126 and eluted from the separator 82.
As described above, the core 100 can be eluted with the water 126 by molding the core 100 with the water-soluble polymer. For this reason, since the equipment for eluting the core 100 can be simplified, the equipment cost can be suppressed and the cost can be reduced.
[0092]
In (c), the first and second cores 101 and 105 for the gas passage and the core 111 for the cooling water passage (shown in (b)) are eluted from the inside of the separator 82 so that the fuel gas passage 83 is formed in the separator 82. , The cooling water passage 85 and the oxidizing gas passage 84 can be opened.
In this state, the separator 82, the anode-side electrode diffusion layer 15, and the cathode-side electrode diffusion layer 35 are taken out of the water tank 125, whereby the separator 82 integrally formed between the anode-side electrode diffusion layer 15 and the cathode-side electrode diffusion layer 35 is formed. obtain.
The separator 82 is shown in an inverted state of the separator 82 shown in FIG.
[0093]
According to the third embodiment described above, the same effects as in the first embodiment can be obtained. That is, according to the third embodiment, the core 100 is formed of a water-soluble polymer, and the fuel gas passages 83... And the oxidizing gas passages 84.
Thus, the core 100 is eluted with the water 126 after the separator 82 is formed, so that the fuel gas passages 83... And the oxidizing gas passages 84.
[0094]
As described above, since the core 100 in the separator 82 can be eluted with the water 126, the fuel gas passages 83 and the oxidizing gas passages 84 can be easily formed in the separator 82.
[0095]
Further, the separator 82 was formed integrally with the anode-side electrode diffusion layer 15 and the cathode electrode diffusion layer 35. Accordingly, the electrical contact resistance between the separator 82 and the anode-side electrode diffusion layer 15 can be suppressed, and the electrical contact resistance between the separator 82 and the cathode electrode diffusion layer 35 can be suppressed. Therefore, a decrease in the output of the fuel cell can be prevented.
[0096]
In addition, according to the third embodiment, the cooling water passages 85 are formed in the separator 82 by using the core 100 of the water-soluble polymer. Since the cooling water passages 85 can be formed in the separator 82, there is no need to form a cooling water passage by stacking a pair of separators as in the related art.
[0097]
As described above, since the pair of separators conventionally required can be integrally formed, electrical contact resistance generated between the pair of separators as in the related art can be suppressed.
As described above, by suppressing the contact resistance, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from lowering.
[0098]
Next, the resistance overvoltage according to the third embodiment will be described based on Table 2.
[0099]
[Table 2]

[0100]
In the second comparative example, the first separator and the second separator are combined without integrating the first and second separators.
The second embodiment is a third embodiment in which a separator is integrated.
[0101]
The resistance overvoltages of the second comparative example and the second example were measured under the following conditions.
That is, the temperature of the cell module is set to 80 ° C., and pure H is used as the anode gas (fuel gas). ₂ And air was supplied as a cathode gas (oxidant gas).
The fuel gas temperature on the anode side was 80 ° C., the oxidant gas temperature on the cathode side was 80 ° C., the fuel gas pressure on the anode side was 50 kPa, and the oxidant gas pressure on the cathode side was 100 kPa. Under these conditions, the current density is 0.883 A / cm ² Was passed.
[0102]
As a result, the resistance overvoltage of the second example could be reduced by 0.027 V per cell module as compared with the resistance overvoltage of the second comparative example.
Thus, as in the second example (third embodiment), it can be seen that by integrating the separator, it is possible to reduce the resistance overvoltage and prevent the output of the fuel cell from lowering.
[0103]
Next, a fourth embodiment will be described.
In the third embodiment, as shown in FIG. 14, the first gas passage core 101 is formed integrally with the anode electrode diffusion layer 15, and the second gas passage core 105 is formed integrally with the cathode electrode diffusion layer 35. The example in which the first gas passage core 101 is separated from the anode-side electrode diffusion layer 15 is formed, but the present invention is not limited thereto. It is also possible to separate and mold.
[0104]
In this case, first, the anode-side electrode diffusion layer 15 is disposed in the cavity 123 of the mold 120 shown in FIG. 15, and the first gas passage core 101 is placed on the anode-side electrode diffusion layer 15. After the cooling water passage core 111 is placed on the first gas passage core 101 and the second gas passage core 105 is placed on the cooling water passage core 111, the second gas passage core 105 is placed on the first gas passage core 111. The cathode-side electrode diffusion layer 35 is mounted.
[0105]
By closing the mold 120 in this state, similarly to FIG. 15B of the third embodiment, the first and second cores 101 and 105 for gas passage, the core 111 for cooling water passage, the anode The side electrode diffusion layer 15 and the cathode side electrode diffusion layer 35 can be set in the cavity 123.
Therefore, in the fourth embodiment, the same effect as in the third embodiment can be obtained.
[0106]
In addition, according to the method for manufacturing a fuel cell separator of the fourth embodiment, the first gas passage core 101 can be formed separately from the anode-side electrode diffusion layer 15, and the second gas passage core 101 can be formed separately. The child 105 can be formed separately from the cathode-side electrode diffusion layer 35.
Thus, the method of forming the first and second gas passage cores 101 and 105 can be appropriately selected from any one of the third and fourth embodiments, thereby increasing the degree of freedom in design. it can.
[0107]
In the above-described embodiment, the polymer electrolyte fuel cells 10 and 80 using the polymer electrolyte as the electrolyte membrane 12 have been described. However, the present invention is not limited to this and can be applied to other fuel cells. .
[0108]
Further, in the first and second embodiments, the example in which the first and second separators 20 and 40 are formed by the injection molding method has been described. However, the present invention is not limited thereto. For example, a hot press molding method or a transfer molding method may be used. Molding is also possible.
The transfer molding apparatus is a method in which a molding material is put into a pot portion separate from the cavity for one shot, and the molten material is transferred to the cavity by a plunger and molded.
[0109]
When the first and second separators 20 and 40 are molded by the hot press molding method, as a resin constituting the first and second separators 20 and 40, for example, a thermosetting resin having acid resistance may be used. A resin composition containing natural graphite, artificial graphite, Ketjen black, acetylene black, or the like, alone or as a mixture, and containing a carbon material in an amount of 60 to 90 wt% is applicable.
Examples of the thermosetting resin having acid resistance include, but are not limited to, phenol and vinyl ester.
[0110]
【The invention's effect】
The present invention has the following effects by the above configuration.
According to the first aspect, a gas passage can be formed by forming a core for forming a gas passage with a water-soluble polymer and eluting the core with water after molding the separator.
As described above, since the core in the separator can be eluted with water, a gas passage can be easily formed in the separator, and the separator can be easily manufactured.
[0111]
Further, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between the separator and the electrode diffusion layer can be suppressed, so that the output of the fuel cell can be prevented from lowering.
[0112]
In the second aspect, the gas passage core for forming the gas passage is formed of a water-soluble polymer, and the gas passage core can be formed by eluting the gas passage core with water after the separator is formed. .
As described above, since the gas passage core in the separator can be eluted with water, the gas passage can be easily formed in the separator, and the separator can be easily manufactured.
[0113]
Further, the separator is formed integrally with the electrode diffusion layer. Thereby, the electrical contact resistance between the separator and the electrode diffusion layer can be suppressed, so that the output of the fuel cell can be prevented from lowering.
[0114]
Furthermore, the cooling water passage is formed in the separator by forming the core for the cooling water passage from a water-soluble polymer and eluting the core for the cooling water passage with water after molding the separator. Since the cooling water passage can be formed in the separator, it is not necessary to form a cooling water passage by overlapping a pair of separators.
As described above, since it is not necessary to overlap the pair of separators, electrical contact resistance generated between the pair of separators as in the related art can be eliminated, and a decrease in the output of the fuel cell can be prevented.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a fuel cell provided with a fuel cell separator (first embodiment) according to the present invention.
FIG. 2 is a sectional view taken along line 2-2 of FIG.
FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;
FIG. 4 is a first process chart illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
FIG. 5 is a perspective view of a core used in a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
FIG. 6 is a second process diagram illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
FIG. 7 is a third process diagram illustrating a method (first embodiment) of manufacturing a fuel cell separator according to the present invention.
FIG. 8 is a sectional view taken along line 8-8 in FIG. 1;
FIG. 9 is a process chart illustrating a method for manufacturing a fuel cell separator according to the present invention (second embodiment).
FIG. 10 is an exploded perspective view of a fuel cell including a fuel cell separator (third embodiment) according to the present invention.
11 is a sectional view taken along line 11-11 of FIG. 10;
FIG. 12 is a first process chart illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 13 is a second process diagram illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 14 is a perspective view of cores (first and second gas passage cores and cooling water passage cores) used in the method for producing a fuel cell separator (third embodiment) according to the present invention.
FIG. 15 is a third process chart illustrating a method for manufacturing a fuel cell separator according to the present invention (third embodiment).
FIG. 16 is a fourth process chart illustrating the method for manufacturing the fuel cell separator according to the present invention (third embodiment).
FIG. 17 is an exploded perspective view showing a conventional fuel cell.
[Explanation of symbols]
10, 80: fuel cell, 15: anode-side electrode diffusion layer (electrode diffusion layer), 20: first separator (separator for fuel cell), 20b: fuel gas passage forming surface (surface of separator), 26, 83: fuel Gas passages (gas passages), 30, 85 cooling water passages, 35 cathode side electrode diffusion layers (electrode diffusion layers), 40 second separators (fuel cell separators), 40b oxidant gas passage formation surfaces, 46 84, oxidant gas passage (gas passage), 50, 100 core, 60, 120 mold, 63, 123 cavity, 63a, 63b, 123a, 123b cavity surface, 66, 126 water, 82 ... Separator (separator for fuel cell), 82b ... Oxidant gas passage forming surface (other side of both sides of separator), 101 ... Core for first gas passage, 105 ... Core for second gas passage, 11 ... cooling water passage core, 82a ... fuel gas passage forming surface (one side of the separator).

Claims (2)

Forming a core for forming a gas passage with a water-soluble polymer;
A step of disposing the core in the cavity of the mold, and disposing an electrode diffusion layer in a gap between the core and the cavity surface;
Filling the cavity with molten resin;
A step of taking out the solidified solid of the molten resin from the cavity after being formed integrally with the core and the electrode diffusion layer,
Forming a gas passage in the surface of the separator with the separator and the electrode diffusion layer by eluting the core with water from the separator. Forming a gas passage core and a cooling water passage core for forming a gas passage and a cooling water passage with a water-soluble polymer,
The gas passage core is arranged facing the cavity surface of the mold, and the electrode diffusion layer is arranged in a gap between the gas passage core and the cavity surface, and cooled at a predetermined interval from the gas passage core. Arranging a core for a water passage;
Filling the cavity with molten resin;
A step of taking out the separator solidified from the molten resin from the cavity after being formed integrally with the core for the gas passage, the core for the cooling water passage and the electrode diffusion layer,
A step of forming a gas passage on the surface of the separator with the separator and the electrode diffusion layer by eluting the gas passage core and the cooling water passage core with water from the separator, and forming a cooling water passage in the separator. A method for producing a fuel cell separator comprising:

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